Carboxy-hydroxy-containing
copolymers

ABSTRACT

A COPOLYMER OF AN UNSATURATED ALIPHATIC ACID HAVING ONLY ONE CARBOXY GROUP, AT LEAST ONE DIFFERENT ETHYLENICALLY UNSATURATED MONOMER AND A BETA-HYDROXYALKYL ESTER OF AN UNSATURATED ALIPHATIC ACID HAVING ONLY ONE CARBOXYL GROUP, SAID COPOLYMER BEING USEFUL IN COATING COMPOSITIONS.

United States Patent Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specifiv cation;matter printed in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE A copolymer of an unsaturated aliphatic acidhaving only one carboxy group, at least one different ethylenicallyunsaturated monomer and a beta-hydroxyalkyl ester of an unsaturatedaliphatic acid having only one carboxyl group, said copolymer beinguseful in coating compositions.

This invention is a continuation-in-part of my copending applicationSer. No. 364,274, filed May 1, 1964 now abandoned and application Ser.No. 117,830, filed June 19, 1961, now abandoned and application Ser. No.593,- 340, filed June 25, 1956, now U.S. Patent No. 3,002,959.

This invention relates to carboxy-hydroxy copolymers which are eminentlysuitable as crosslinking agents with diisocyanates, epoxides andaminoplast resins. More particularly, this invention relates to suchcopolymers having an acid value of from about 1 to 50.

The carboxy-hydroxy copolymers of this invention are esters of acopolymer of a short chain alpha-beta unsaturated mono-carboxylic acidand a vinyl monomer having a single active terminal vinyl group, whereinthe ester substituents are formed by means of a monoepoxide. Thereactions involved in the preparation of these carboxyhydroxy copolymersare the carboxy-epoxy reactions between the carboxyl group of thealpha-beta unsaturated acid and the monoepoxide, whereby the hydroxyester is formed, and the copolymerization reaction wherein theunsaturated mono-carboxylic acid, or its ester, and the vinyl monomercopolymerize to form the copolymer.

In the reaction of a carboxyl group with an epoxide group, twomonohydroxyester substituents are possible. Each portion of the estersubstituent derived from the monoepoxide, that is, the alcoholic portionof the ester substituent, contains one alcoholic hydroxyl group on acarbon atom either alpha or beta to a carbonyl carbon atom. Hence, inthe copolymers resulting from the process of this invention, eachhydroxyl in the molecule is attached to a carbon atom linked to acarbonyl group through the oxygen atom or to a carbon atom adjacent to acarbon atom linked to a carbonyl group through the oxygen atom of theester linkage.

In preparing the copolymers of this invention, one method is to esterifythe alpha-beta unsaturated monocarboxylic acid to form the hydroxy-esterand then to copolymerize this resulting hydroxy-ester with the vinylmonomer. Another method is to copolymerize the alphabeta unsaturatedmonocarboxylic acid with the vinyl monomer and then to esterify thecopolymer thus formed using a monoepoxide to form the carboxy-hydroxycopolymer. A sufficient amount of the acid is used so that the acidvalue of the resulting copolymer is at least about ice 1. The upperlimit for the acid number is not critical and may be as high as or even50. Advantageously, the acid value is between about 12 and 20.

In accordance with Ser. No. 593,340, now U.S. Patent No. 3,002,959,however, it was discovered that the hydroxy-ester and the copolymer canbe made by concomitant reactions, through the combination of the threereactants and the use of two catalysts, a carboxy-epoxy catalyst and avinyl polymerization catalyst. Thus, by the use of two catalysts, acarboxy-hydroxy-containing copolymer is prepared by copolymerizing analpha-beta unsaturated monocarboxylic acid with a monovinyl compoundwhile concomitantly the alpha-beta unsaturated acid is reacted with amonoepoxide to form a hydroxyester. More specifically, a styrene-hydroxypropyl acrylate or vinyl toluene-hydroxy propyl methacrylate copolymeris prepared by combining acrylic acid or methacrylic acid, propyleneoxide, and styrene or vinyl toluene, and the esterifiedcopolymer-containing carboxyl groups is readily formed in the presenceof an amine, an amine salt, or a salt of a quaternary ammoniumhydroxide, etc., as a catalyst for the carboxy-epoxy reaction and aperoxide or hydroperoxide, etc., as a catalyst for the copolymerizationreaction. Again, sufficient acid is employed so that the acid value ofthe resulting copolymer is between about 1 to 50.

In preparing the carboxy-hydroxy copolymers following the practice ofSerial No. 593,340, now U.S. Patent No. 3,002,959 the three reactantsand the two catalysts are combined in the presence of a solvent which isinert insofar as the reactions are concerned, and refluxed until thecarboxy-epoxy esterification and concomitant polymerization reactionsare substantially complete, as indicated by a relatively constant acidvalue, and a solids content approaching the theoretical for completeconversion. The reflux period generally is from four to ten hours. Theacid value continues to decrease until the reaction is substantiallycomplete, whereupon the acid value remains substantially constant. Thereflux temperature is dependent upon the boiling point of the lowestboiling substituent, and the amount of the substituent present in themixture. Thus, when propylene oxide, along with a higher boilingsolvent, is used, the reflux temperature is generally C. to C. Ingeneral, the reaction temperature is between 60 C. and the refluxtemperature of the mixture. It is noted that this invention inovlves theuse of two catalysts, where one catalyst is an inhibitor of the reactionpromoted by the other. Amines, the example, are inhibitors of vinylcopolymerization reactions. Accordingly, for maximum production of estergroups, as Well as ultimate conversion to copolymer, it is desirablethat the two catalysts be in balance. If too much amine or similarcatalyst is used the acid value will reach a leveling-oil point, but theconversion to copolymer will be low. If too much peroxide or otherpolymerization catalyst is employed, conversion to polymer issatisfactory but the leveling off of the acid value, indicating extentof esterification of carboxyl groups, will not be reached to the properdegree. In general, the amount of peroxide is one to four percent,depending upon the monomers, and the carboxyepoxy catalyst is in therange of 0.5 to 6 percent by weight based on the reactants, dependingupon its basicity. Weakly basic catalysts such as tertiary amines areused in quantities of from three or four to six percent, while less ofthe stronger bases such as primary amine is used within the range.

Thus, as claimed in Serial No. 593,340, now U.S. Patent No. 3,002,959, aone-step process was provided for preparing carboxy-hydroxy copolymerswherein the aliphatic acid and the monoepoxide are reacted using amineor a quaternary ammonium compound as a catalyst, while 3 the unsaturatedaliphatic acid is concomitantly copolymerized with the ethylenicallyunsaturated monomer. In the preparation of these carboxy-hydroxycopolymers for maximum yields, it is also desirable to maintain a properproportion of reactants to solvent. When too much solvent is used, thecarboxy-epoxy reaction proceeds normally but.

there is a low conversion to polymer. If too little solvent is employed,production of ester groups from the carboxyl-epoxide reaction is lowwhereas the polymerization reaction proceeds without difliculty. Formost purposes, it is desirable to employ the solvent in a ratio of thecombined three reactants to solvent of from 1:0.4 to l: 1.

Among the monoepoxides suitable for the preparation of ester groups inaccordance with this invention are substituted alkyl compounds, as wellas ethers and esters. One class of carboxy-hydroxy copolymers resultsfrom the reaction of the carboxyl groups of the alpha-beta unsaturatedacid, with a saturated hydrocarbon, ether, ester, etc., having athree-membered epoxide ring, said epoxy compound being free of otherreactive groups. Examples are oxirane, or ethylene oxide, as well assaturated alkyl oxiranes, for instance, methyl oxirane, or propyleneoxide, butene-Z-oxide, etc. Among others are esters and etherscontaining only one three-membered epoxide substituent, each free ofother reactive groups. Examples are phenyl glycidyl ether, isopropylglycidyl ether, butyl glycidyl ether, glycidyl benzoate, glycidylacetate, etc.

Valuable alpha-beta unsaturated acids for use in the preparation of thecopolymer are short chain alpha-beta unsaturated aliphaticmonocarboxylic acids such as acrylic acid, methacrylic acid and crotonicacid. By short chain alpha-beta unsaturated acids are intended those ofnot more than twelve carbon atoms. Included are half-esters of maleicand fumaric acids formed with saturated alcohols of from one to tencarbon atoms.

Copolymerized with the alpha-beta unsaturated acid, or the hydroxy esterof the alpha-beta unsaturated acid, is a monomer copolymerizabletherewith, containing a single active CH =C group, including a terminalmethylene group, which undergoes addition polymerization to producelinear polymers, in other words, a vinyl compound. Particularlyimportant are vinyl aromatic compounds, for instance, styrene, vinyltoluene, alpha-methyl styrene, the halostyrenes, etc., having a singlevinyl group and free of other substituents capable of reacting with anunsaturated acid, i.e., a monofunctional vinyl aromatic compound. Alsovaluable are saturated alcohol esters of acrylic, methacrylic andcrotonic acids. Examples of monofunctional vinyl aromatic monomers areisopropenyl toluene, the various dialkyl styrenes, ortho-, meta- J andpara-chloro styrene, bromo styrenes, fluoro styrenes,

cyano styrenes, vinyl naphthalene, the various alpha-substitutedstyrenes, e.g., alpha-methyl styrenes, alpha-methyl para-methylstyrenes, as well as various di-, triand tetra-chloro, bromo and fluorostyrenes. Acrylic, methacrylic and crotonic esters of saturated alcoholsinclude the methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,(sec)butyl, (terObutyl, amyl, hexyl, heptyl, octyl, decyl, dodecyl, etc.esters of acrylic, methacrylic, and crotonic acids. Thus, preferredvinyl monomers include alpha-beta unsaturated monocarboxylic acid estersof saturated monohydric alcohols, the acids having not more than fourcarbon atoms and the alcohols having not more than twenty carbon atomsand monofunctional vinyl aromatic compounds.

Other known vinyl monomers can, of course, be used in the preparation ofthe carboxyl-containing vinyl copolymer. Desirable monomers includevinyl aliphatic cyanides of not more than four carbon atoms, forexample, acrylonitrile and methacrylonitrile, as well as monovinylethers, e.g., ethyl vinyl ether, ethyl methallyl ether, vinyl butylether, methyl vinyl ether and others of not over twenty carbon atoms.Included also are unsaturated monohydric alcohol esters of saturatedmonobasic acids wherein the alcohols contain a single vinyl group andthe acids til) have not more than twenty carbon atoms, for instance,vinyl acetate, vinyl stearate, and the allyl, methallyl, and crotylesters of propionic, butyric and other acids. Not only the vinylmonomers themselves, but mixtures of the vinyl monomers can becopolymerized with the alphabeta unsaturated acids to form thecarboxyl-containing vinyl copolymer. A particularly desirable mixture isa combination of an acrylic or methacrylic ester with styrene or vinyltoluene.

In the preparation of ester groups, any of the catalysts which areactivators for epoxide-carboxyl reactions can be used. Thesecpoxy-carboxy catalysts are generally basic materials and are well knownin the art, for example, amines, amine salts, quaternary ammoniumhydroxides and quaternary ammonium salts, such as dimethylaminomethylphenol, benzyl trimethyl ammonium hydroxide, benzyl trimethyl ammoniumchloride etc. Particularly useful for this purpose are the quaternaryammonium hydroxides and halides.

Included among catalysts for promoting the polymerization of thealpha-beta unsaturated monocarboxylic acid with the vinyl monomer arehydrogen peroxide, various organic peroxides, for example, ascaridol,acetyl, and benzoyl peroxide, dibutyryl and dilauryl peroxides, caprylylperoxide, as well as partially oxidized aldehydcs which can containperoxide, ureaperoxide, succinic acid peroxide, and the like. Otherperoxides are fatty acid peroxides, such as coconut oil peroxides,stearic peroxide, lauric peroxide, and oleic peroxide. Also intended arealcoholic peroxides such as tertiary butyl hydroperoxides and otherperoxides such as cumene hydroperoxide, tertiary butyl perbenzoate,hydroxyheptyl peroxide and chlorobenzoyl peroxide. Other free radicalpromoting catalysts such as azobisisobutyronitrile can also be used.

By combining the three reactants according to Serial No. 593,340, nowPatent No. 3,002,959, and application Serial No. ll7,830, filed June 19,1961, a Wide variety of carboxy-hydroxy copolymers can be prepareddepending entirely upon the ratio of vinyl monomer to the other tworeactants. Carboxy-hydroxy copolymers particularly useful in thecoatings field are generally prepared so that the carboxy-hydroxycopolymer contains from five to seventy-five percent by weight, based onthe copolymer of the hydroxy ester of the alpha-beta unsaturatedmonocarboxylic acid. Hence, the remaining ninety-five to twenty-fivepercent of the copolymer is vinyl compound. The maximum amount ofmonoepoxide will, generally, of course, be that equivalent to less thanthe unsaturated monocarboxylic acid, such that the acid value of the resulting copolymer will be about 1 to 50. In general, copolymers have anaverage of from four to one hundred hydroxyl groups per molecule, andweights per hydroxyl group of not less than 116. It has been noted thatin the incorporation of the carboxy-hydroxy copolymers, a solvent isemployed as the reaction. medium. Desirable solvents for this purposeare ketones, Cellosolves and aromatic hydrocarbons as well ascombinations of aromatic hydrocarbons with a ketone or Cellosolve, forexample, acetone, methyl ethyl ketone, methyl isobutyl ketone,diisobutyl ketone, Cellosolve, Cellosolve acetate, and mixtures ofl-retones and Cellosolves with xylene, toluene, benzene, etc.

As pointed out above, the carboxy-hydroxy copolymers of this inventionare useful in the coatings industry and are eminently suitable ascrosslinking agents with diisocyanates, epoxides, and aminoplast resins.

The presence of the carboxyl groups in the copolymer prepared accordingto the present invention are of particular importance in that thesecarboxyl groups impart to the copolymer a unique compatibility with thecrosslinking agent, such as an alkylated aminoplast resin, andconsequently these copolymers produce a crosslinked product having avery high gloss. On the other hand, the absence of the carboxyl groupsresults in the production of crosslinked products having substantiallyless gloss.

The presence of the carboxyl groups in the copolymer of this inventionis also of particular significance in imparting stability to thecopolymer when the copolymer is present in an uncured mixture containingthe crosslinking agent, such as a diisocyanate. This stability featureis important because these copolymers are generally sold in admixturewith the crosslinking agent. It is therefore of paramount importancethat no substantial crosslinking reaction take place between thecopolymer and the crosslinking agent during the shipping and storageperiods.

The consumer who purchases the admixture and who coats various articleswith it, usually follows a procedure whereby he fills a dip tank withthe admixture and then clips the articles in the tank. He then removesthe coated articles from the tank and then bakes them. During the bakingperiod, a self-crosslinking reaction takes place between the copolymerand the crosslinking agent. Since it is customary to simply replenishthe contents of the dip tank as they become depleted, it is apparentthat portions of any particular admixture batch may remain in the diptank for extended periods of time. It is again of paramount importancethat no substantial crosslinking reaction take place between thecopolymers and the crosslinking agent during the period of time in whichthe admixture is in the dip tank.

It has been found that when a crosslinking agent, such as an alkylatedaminoplast resin, is employed, and the acid value of the copolymersproduced according to the present invention approaches zero, an acidcatalyst must be added to the copolymer-crosslinking agent mixture inorder to produce a self-crosslinking mixture. This mixture, however, isnot satisfactorily stable. The copolymers of this invention require noadditional acid catalyst and yet they are surprisingly stable whenpresent in an uncured mixture containing the crosslinking agent. If thestability of the mixture is not of primary concern, small amounts ofacid catalyst may be added to the mixture in some instances.

For a further understanding of the invention, reference is made to thefollowing specific examples, the viscosities given being Gardner-Holdtviscosities run at C. These examples are intended to be illustrative ofthe invention only, since different embodiments can be made withoutdeparting from this invention.

Example 1 A carboxy-hydroxy containing copolymer is prepared by charginginto a two liter flask equipped with agitator, thermometer and refluxcondenser, 535.0 grams of methyl isobutyl ketone. To this solvent isadded 178.5 grams of propylene oxide, 221.6 grams of acrylic acid and400.0 grams of styrene. The ratio of the three reactants to solvent usedis 1.0 to 0.67. In addition to the 178.5 grams of propylene oxide, a 10percent (17.9 gram) excess is used to compensate for any loss due tovolatility; the unreacted portion being distilled off at the completionof the process. To this mixture, as catalysts, are added 16.0 grams ofbenzoyl peroxide, and 22.9 grams of a per cent solution of benzyltrimethyl ammonium hydroxide in methanol. The contents of the flask areheated to reflux temperature (7580 C.) at which time an exothermicreaction occurs and heating is discontinued. After the exothermsubsides, heat again is applied to maintain refluxing until an acidvalue of 2.7 is reached (approximately ten hours). The flask contentsare further heated to about 117 C. while distilling off any unreactedpropylene oxide. After removal of the excess propylene oxide, thereaction mixture is cooled to about 70 C. and poured into a suitablecontainer. This process results in a 50 copolymer of styrene and hydroxypropyl acrylate by combination of these proportions; 22.3 parts byweight of propylene oxide, 27.7 parts by weight of acrylic acid and 50.0parts by weight of styrene, a total of 100 parts for the threereactants. The copolymer solution thus prepared has a viscosity of Z(Gardner-Holdt) and a 58.5 percent solids content (two hours at 150 C.).

Example 2 A carboxy-hydroxy-containing copolymer is prepared accordingto Example 1 by combining 44.4 grams (11.1 parts by weight) of propyleneoxide, 55.6 grams (13.9 parts by weight) of acrylic acid, and 300.0grams (75.0 parts by weight) of styrene (parts by weight based on atotal of for the three reactants). 266.5 grams of xylene are used as asolvent. The ratio of the three reactants to solvent used is 1 to 0.67.As catalysts are added 4.0 grams of benzoyl peroxide and 5.7 grams of a35 percent solution of benzyl trimethyl ammonium hydroxide in methanol.Refluxing of the mixture is continued until an acid value of 1.5 isreached (approximately 12 /2 hours). The 7525 styrene-hydroxy propylacrylate copolymer solution prepared has a solids content of 51.3percent (two hours at (3.).

Example 3 A carboxy-hydroxy-containing copolymer is prepared accordingto Example 1 by combining 66.9 grams (22.3 parts by weight) of propyleneoxide, 83.1 grams (27.7 parts by weight) of acrylic acid, 75.0 grams (25parts by weight) of styrene and 75.0 grams (25 parts by weight) ofmethyl acrylate (parts by weight being based on a total of 100 parts forthe four reactants), in the presence of 300.0 grams of xylene. The ratioof the four reactants to solvent used is one to one. To this mixture areadded as catalyst three grams of benzoyl peroxide and 8.6 grams of a 35percent solution of benzyl trimethyl ammonium hydroxide in methanol. Inaddition to the 66.9 grams of propylene oxide, a ten percent excess (6.7grams) additional are used to compensate for any loss due to volatility;the unreacted portion being distilled off at the completion of theprocess. The reaction mixture is heated to reflux temperature at whichtime an exothermic reaction takes place and heating is discontinued.After the exotherm subsides, heat is again applied and refluxing iscontinued until an acid value of 3.7 is reached (approximately elevenhours). Unreacted propylene oxide is distilled off, the contents of thefiask are cooled to around 70 C. and are then poured into a suitablecontainer. This styrene-methyl acrylate-hydroxy propyl acrylatecopolymer solution (25-25-50), prepared from the proportions above, hasa solids content of 43.1 percent (two hours at 150 C.).

Example 4 According to the procedure outlined in Example 1, acarboxy-hydroxy-containing copolymer is prepared from 66.9 grams (22.3parts by weight) of propylene oxide, 83.1 grams (27.7 parts by weight)of acrylic acid and 150.0 grams (50.0 parts by weight) of vinyl toluene(parts by weight being based on a total of 100 parts for the threereactants). As solvent 200.0 grams of xylene are added. The ratio of thethree reactants to solvent used is one to 0.67. To this mixture areadded as catalysts, 6.0 grams of benzoyl peroxide and 8.6 grams of a 35percent solution of benzyl trimethyl ammonium hydroxide in methanol. Inaddition to the 66.9 grams of propylene oxide, 6.7 grams (ten percentexcess) are added to allow for any loss due to volatility; the unreactedportion being distilled off at the completion of the process. Thereaction mixture is refluxed until an acid value of 1.2 is obtained(approximately 10% hours). The 50-50 vinyl toluenehydroxypropyl acrylatecopolymer solution thus prepared has a solids content of 46.2 percent(two hours at 150 0.).

Example 5 A carboxy-hydroxy containing copolymer is prepared accordingto Example 4 by combining in the presence of 100.0 grams of xylene and100.0 grams of ethyl Cellosolve, 65.3 grams (22.3 parts by weight) ofpropylene oxide, 81.0 grams (27.7 parts by weight) of acrylic acid and146.4 grams (50.0 parts by weight) of vinyl toluene (parts by weightbeing based on the total of 100 parts for the three reactants). Theratio of reactants to solvent used is one to 0.67. Benzoyl peroxide inthe amount of 6.0 grams and triethanolamine in the amount of 18.0 gramsare added as catalysts. The 50-50 vinyl toluenehydroxypropyl acrylatecopolymer solution resulting from the proportions above has an acidvalue of 3.7 (approximately ten hours refluxing), and a solids contentof 43.9 percent (two hours at 150 C.).

Example 6 A carboxy-hydroxy containing copolymer is prepared accordingto Example 1, by combining in the presence of 267.0 grams of methylisobutyl ketone, 80.4 grams (20.1 parts by weight) of propylene oxide,119.6 grams (29.9 parts by weight) of methacrylic acid, and 200.0 grams(50.0 parts by weight) of vinyl toluene (parts by weight being based ona total of 100 parts for the three re- Example 7 According to theprocess outlined in Example 1, a carboxy-hydroxy containing copolymer isprepared in the presence of 200.0 grams of methyl isobutylketone bycombining 112.2 grams (37.4 parts by weight) of butyl hydrogen maleate,37.8 grams (12.6 parts by weight) of propylene oxide, and 150.0 grams(50.0 parts by weight) of methyl acrylate (parts by weight being basedon the total of 100 parts for the three reactants). The ratio of thethree reactants to solvent used is one to 0.67. Six grams of benzoylperoxide and 2.5 grams of a 60 percent aqueous solution of benzyltrimethyl ammonium chloride are used as catalysts. The copolymerresulting from the combination of the proportions above is a 50-50methyl acrylate-hydroxypropyl butyl maleate copolymer solution with anacid value of 12.9 (refluxing for approximately ten hours) and a solidscontent of 40.7 percent (two hours at 150 C.).

Example 8 According to the procedure outlined in Example 1, acarboxy-hydroxy containing copolymer is prepared by combining in thepresence of 200.0 grams of methyl isobutyl ketone, 101.4 grams (33.8parts by weight) of phenyl glycidyl ether (weight per epoxide=150), 48.6

grams (16.2 parts by weight) of acrylic acid, and 150.0 grams (50.0parts by weight) of styrene (parts by weight being based on a total of100 parts for the three rcactants). The ratio of the three reactants tosolvent used is one to 0.67. As catalysts, 6.0 grams of benzoyl peroxideand 5.0 grams of a 60 percent aqueous solution of benzyl trimethylammonium chloride are added. The mixture is refluxed until an acid valueof 3.4 is reached (approximately eight hours). The above proportionsresult in a 50-50 styrene-acrylic acid ester of phenyl glycidyl ethercopolymer solution, with a solids content of 55 percent (two hours at150 C.).

Example 9 A carboxy-hydroxy containing copolymer is prepared tit) and150.0 grams (50.0 parts by weight) of vinyl toluene (parts by weightbeing based on a total of 100 parts for the three reactants). The ratioof the three reactants to solvents used is one to 0.67. As catalysts areadded six grams of benzoyl peroxide and five grams of a 60 percentaqueous solution of benzyl trimethyl ammonium chloride. The mixture isheated to reflux temperature, at which time an exothermic reactionoccurs and heating is discontinued. After the exotherm subsides, heat isagain supplied and refluxing is maintained until an acid value of 3.8 isreached (approximately 5 /2 hours). The -50 vinyl toluene-acrylic esterof butyl glycidyl ether copolymer solution prepared from the proportionsabove has a solids content of percent (two hours at 150 C.).

In accordance with this invention, it has been found that thecombination of an aminoplast resin with a carboxyl containing hydroxylcopolymer, such as the copolymer-urea aldehyde composition disclosed inSerial Number 593,340, now U.S. Patent No. 3,002,959, and applicationSerial Number 117,830, filed June 19, 1961, yields compositions havingoutstanding properties. Such copolymer-aminoplast resin compositionslend themselves very readily to the formation of industrial finishes.They are excellent coatings for metal surfaces, such as for stoves,refrigerators, washers, driers, and other appliances as well asautomobiles, toys, and the like.

Aminoplast resins, as contemplated herein, include alkylated condensatesformed by the reaction of aminotriazines and amino-diazines withaldehydes. It is known that various amines and amides will condense inthe presence of alcohols with aldehydes to form alkylated aldehyde-amineand aldehyde-amide condensates. Thus, urea, thiourea, and varioussubstituted ureas and urea derivatives will react with aldehydes, suchas formaldehyde to form alkylated condensates, e.g., methylol ureas,etc. Similarly, it is well known that melamines, such as melamine itselfand benzoguanamine will react with aldehydes, particularly formaldehyde,to form melaminealdehyde condensates. Various other amines and amidescan similarly be reacted with formaldehyde, etc., to form alkylatedcondensates which are alkylated amine aldehyde or amide aldehyde resinsor condensates. Alkylated condensates result when the amino aldehyde oramide aldehyde resin is prepared in the presence of alcohols such asmethyl, ethyl, propyl, butyl, isobutyl, octyl and decyl alcohol, thesesolvents actually becoming a part of the resulting product. In general,alkylated urea or melamine aldehyde condensates of dilferent degrees ofcondensation can be used so long as they are soluble in aromatichydrocarbons or mixtures of these with other solvents. Alkylatedmelamine-aldehyde condensates, however, are the preferred aminoplastresins.

The proportions of the carboxy-containing hydroxyl copolymer and theaminoplast resin will depend on the desired properties of the coatingwhich results on curing at a temperature of C. to 150 C. It is usuallypreferred that the composition contain 5 to 50 percent aminoplast resinand about .2 to 4 percent acid, the remainder being a comonomercopolymerizable therewith. Based on the foregoing, this invention thuscontemplates a heat hardenable coating composition especially forapplication to metal, based on a mixture of (l) 50 to percent of athermoplastic copolymer of (a) 0.2 to 4 percent acrylic acid,methacrylic acid, crotonic acid or half acidesters of maleic and fumaricacids, (b) 1 to 71 percent of a hydroxy ester of an acid of group (a)and a monoepoxide such as 1,2-alkylene oxides, aryl 1,2-alkylene oxides,monoglycidyl ethers and monoglycidyl esters, each having not over 10carbon atoms and (c) 25 to 95 percent, the total being of anethylenically unsaturated monomer copolymerized therewith; with (2) 5 to50 percent of an aminoplast resin. In a specific embodiment, theinvention includes a heat hardcnable coating composition based on themixture of (l) 50 to 95 percent thermoplastic copolymer of (a) 5 to 30percent hydroxypropyl acrylate, methacrylate or crotonate, (b) 1 to 4percent crotonic, acrylic or methacrylic acid and (c) 66 to 94 percent,the total being 100 of at least one other copolymerizablemonoethylenically unsaturated monomer and (2) 5 to 50 percent of theaminoplast resin.

Four additional blends and films are prepared in the same manner asabove. The reactants and quantities used and the proportions of thecured films are listed in the following table:

ene Methyl isobutyl keton Urea-form- Copolymer aldehyde solution resinsolu- Curing Blend (parts) tion (parts) temp, C. Properties curing time,min.

4 200 Tough, flexible, fair mar resistance.

20 6.8 200 Very tough and more flexible than Blend 10b. good marresistance and adhesion.

20 10. 7 P100 Extremely tough and hard, very good adhesion, excellentmar resistance.

10c 20 16.0 200 Fairly brittle, extremely hard, good adhesion, excellentrnar resistance.

These coatings are exemplified further by the following preparations:

Example 10 Example 11 Parts b Material Units weigh i Parts by MaterialUnits weight 1 1 iigigii c iic i de 0 0 3 3 Propylene oxide (10 percentexcess by Styrene 232:8 Weight) 9 0 e gy peroxide 3-3 g gfg g 35% e e IMethyl isobutyl keton 180- 0 Benzoyl Pemmde 8 0 0 3 0 In accordance withExample 1, the 30 parts of propylene oxide, 37.2 parts of acrylic acid,232.8 parts of styrene, 6 parts of benzoyl peroxide, 120 parts of xyleneand the 180 parts of methyl isobutyl ketone are heated with agitation toreflux (80 C. to 90 C.). At this temperature an exothermic reactionoccurs and heating is discontinned. After the exotherm subsides heat isagain applied to maintain refluxing (raising the temperature to 117 C.as reflux permits). After 10 hours of refluxing the acid value of thesolution is 40.5. Accordingly, .3 gram of benzyl trimethyl ammoniumacetate is added followed one and one-half hours later by anotheraddition of .6 gram of benzyl trimethyl ammonium acetate. The solutionis further heated until its acid value is 10.7. The final product, astyrene-hydroxy propyl acrylate-acrylic acid copolymer solution having asolids content of 47.9 percent, has an acid value of 22.3 (solidsbasis).

In a suitable container, 20 parts of the above copolymer solution (47.9percent solids) and 1.8 parts of a ureaformaldehyde resin solution areblended and 3 mil films Benzyl trimethyl ammonium acetat As in theprocedure of Example 10, the above materials in the amounts shown areheated to reflux (80 C. to 90 C.), at Which temperature an exothermicreaction occurs. After the exotherm subsides the reaction mixture isagain heated to maintain refluxing (raising the temperature to 122 C. asreflux permits) until an acid value (solution) of 2.6 is reached (about9 hours). The resulting copolymer solution at a solids content of 44.8percent has an acid value of 5.8 (solids basis). Blends are made of theabove 44.8 percent solids copolymer solution with the percent solidsurea-formaldehyde resin solution described in Example 10 in the same wayas the blends of Example 10. Films are also prepared from the blends.The following table lists the quantities of the reactants used, thecuring schedule of the films, and a comparison of the properties of thecured films.

C op olym er Urea-formalsolution dehyde resin Curing Curing Blend(parts) solution (parts) temp, 0. time Properties 118 30 4 200 15Brittle.

11b 30 5.6 200 15 Less brittle than 11a, fair mar resistance.

11c 30 9.6 200 15 Very hard, good adhesion and good mar resistance.

11d 30 15 200 15 Tough, hard, very good mar resistance,

most flexible oi the tour.

Minutes.

of this blend (Blend 10a) are drawn down on glass plates. Theurea-formaldehyde resin solution used is a 60/30/10 butylatedurea-formaldehyde resin/butanol/ xylol solution. At curing schedules of200 C. for 15 minutes and 200 C. for 30 minutes, hard, mar resistant,thermoset films are produced.

Six additional blends and films are prepared in the same Way as above.However, these blends have a morpholine salt of para-toluene sulfonicacid added to them as a catalyst. The following table lists thequantities of the reactants used. the curing schedule of the films, anda comparison of the properties of the cured films.

Catalyst Urea (25 percent Gopolymer formaldehyde solution in solutionresin solution ethanol) Curing Curing Blend (parts) 1 (parts) 2 (parts)temp, C. tunes 3 Properties 119 3O .9 150 30 lligrnrteisistance betterthan Blend 11d,

r c. 150 30 Good hardness, flexibility and mar resistance. 200 Less marresistance and less flexibility than Blend lli 150 30 Good marresistance, more ilexihle than Blend llf. 200 20 Lessfmar resistanceflexibility than Blend 11 150 30 Good mar resistance, less flexible thanBlend 11g. 150 30 Poor to fair mar resistance. 113 30 9 6 4 .27 150 30Very much like blend 110.

1 44.8 percent solution. 2 60 percent solution. 3 Minutes. 4 Tlenzyltl'imethyl ammonium acetate.

Example 12 are added to the flask contents. The temperature is againraised to reflux and refluxing is continued until a 98 per- Pa ts v nocent conversion to copolymer is obtained. The resulting Material Unitsweight Propylene oxide 7 4. 3 Acrylic acid 8.5. l Sty|ene. l5q.0 Benzoylperoxide. b. D Xylene 120. i)

letliy isobutyl ketono. .i 180. 0 Benzyl trimethyl ammonium acetate i i3.0

Following Example 10, the above materials in the amounts shown areheated to reflux (80 C. to 90 C.), at which temperature an exothermicreaction occurs.

copolymer solution (copolymer 1), at 45 percent resin solids has aviscosity of J and an acid value of 13.8 (solids basis). The viscosityof the copolymer solution, when reduced to 40 percent resin solids withxylene is G.

To make as pastel blue, metallic automobile enamel using the foregoingcopolymer, one part of a pigment paste, previously prepared by mixingthe solution of the copolymer and phthalocyanine blue in a sand grindmill in a ratio of four parts copolymer (based on solids) to one partphthalocyanine blue, is stirred with an additional After the exothermsubsides, heat rs apphed to the flask 62,25 parts, based on solids, ofthe copolymer, employed OII i to maintain lfifluxifig f h temperature asa 45-percent solution. While this mixture is being to l26 C. as r fl pUntil all 861d Value stirred, 16.75 parts of an isobutylatedmelamine-formalde- IiOIl) 0f is Tfiached (about 13 At i end hydc resinsolution is added containing 50 percent resin f his time, additionalParts of pyl ({xldfi P in isobutyl alcohol. In addition, 6.46 parts of aparaadded to the flask Contents and th acti m 1S toluenesulphonamide-modificd melaminc-forrnaldehyde ate 10 Over a Period of SIXd one-half resin solution is added containing 66 percent resin inxyhOllFS, distilling OIT y Propylene 0X1d at Th6 lcne. Stirring iscontinued and 6.93 parts acetone and 1.73 611d 05 this p The resulting Yy f yP P Y parts xylene are added. This mixture is then stirred untilacrylate/acrylic acid copolyrner SOlLitlOti having a SOlId S 40 a moothenamel forms, The enamel when applied {0 an content of 47.8 percent, hasan acid value on SOlldS basis t bil bod d b k d at 250 F, h ll t fil of30.7. properties.

Blends are made of the above copolymcr solution With Example 14 theurea-formaldehyde resin solution described in Exampic 10 and amorpholine salt of para-tolucnc sulfonic In a three neck, round bottomflask equipped with an acid as a catalyst in accordance with thecatalyzed blends agitator, thermometer, dropping funnel and reflux conofExample 11. In addition, 10 parts of methyl isobutyl denser, 1050 partsof xylene are heated to reflux. To this ketone are incorporated in threeof the blends. The folhot solvent the first of two monomer additions ismade lowing table lists the quantities of the reactants used, consistingof 270 parts of methyl methacrylate, 45 parts the curing schedule and acomparison of the properties of methacrylic acid, 180 parts of styreneand parts of of th cured fil cumene hydroperoxidc. The temperature isheated to the Copolyrner Urea- Methyl solution (47.8 formaldehydeisobutyl percent resin solution Catalyst kctone solids) (parts (parts by(parts by (parts by Curing (tiring Blend by weight) weight) Weight)weight) temp, C. time (min.) Properties 12:1. 30 ii .7 10 30 Moreflexible than Example 1! cures, good mar resistance. 12b 30 10. 3 .8 15030 Brittle, but very good mnr resistance. 12o... 30 3.1) .7 10 150 30Good toughness, poor mar resistance. 12d 3|) 2. 7 .7 10 150 30 Slightlyinferior to Blend 12c cure in toughness and mar resistance.

'60 percent solution.

Example 13 reflux temperature of 262 F., and at this temperature,

In a equipped with an agitator, thermometer, dropping funnel p y y i p sy acid, 330 parts of styrene and 30 parts of cumene hydroand refluxcondenser, 3632.1 parts xylene and 682.4 parts on peroxide. The flaskcontents are permitted to reflux for butanol are heated to reflux. Tothis hot solvent over a pca one hour and 15 minutes and then cooled to190 F. At nod of 1% hours 1104's Parts of methyl methacrylate this ternerature 8 5 arts of bcnz ltrimeth lammoniurn 1121.6 parts of butylmethacrylate, 426.7 parts of butyl memo p t l y d d th acrylate, 468.8parts of ethyl acrylate, 375.0 parts of methi; so u 10), are a e 1 3acrylic acid and 37.5 parts of benzoyl peroxide are added. 1'0 over amy'mmute penod 9, Parts fine e The mixture is heated at the refluxtemperature, 265 F., are added- The composltlon 1S agaln heated to thefor two hours The reaction product is then cooled to 180 refluxtemperature and held at this temperature until a 98 F. and 21.2 parts ofa 40-percent solution of benzyl tripercent conversion to copolymer isobtained. The resultmcthyl ammonium methoxidc in methanol are added. ingcomposition is reduced to 50 percent resin solids with Over a period of1% hours, 253 parts of propylene oxide 75 butanol. This 50 percent resinsolids composition has a 13 viscosity of X-Y and an acid value of 14(solids basis). The viscosity of the copolymer solution when reduced to40 percent resin solids is L].

By the pigmentation procedure described in connection with Example 13, asolid white enamel is made from this copolymer solution. A sand grind ismade from 21.07 parts of titanium dioxide, 4.26 parts of xylene and 2.67parts of the copolymer solution (based on solids). This grind is thenmixed with another pigment paste made from 42 parts (based on solids) ofthe copolymer solution, 18.02 parts (based on solids) of a melamineformaldehyde resin made in normal butyl alcohol and having a viscosityof GK at 50 percent solids, 3 parts of Solvesso 100, an aromaticpetroleum hydrocarbon, 4 parts of toluene, 2 parts of methyl ethylketone and .88 part of butyl Cellosolve. This mixture is stirred until asmooth enamel results, applied to an automobile body and baked for 30minutes at 250 F. The resulting finish has very good properties.

The foregoing copolymer solution is blended on a solids basis withalkylated aminoplast resins in a ratio of 70 parts copolymer (solidsbasis) to 30 parts of each of the following resins:melamine-formaldehyde resin made in butyl alcohol and paratoluenesulfonamide (66 percent resin solids), benzoguanamine-formaldehyde resinmade in butyl alcohol (60 percent resin solids) butylatedmelamine-formaldehyde resin (55 percent resin solids), isobutylatedmelamine-formaldehyde resin (55 percent resin solids), butylatedurea-formaldehyde resin (50 percent resin solids). Films made from allof these blends, when compared with one fatty acid modified alkyd resincontaining 22.8 percent lauric acid and another one modified with 40percent soya acids, yield equivalent solvent resistance properties andsuperior resistance to lipstick and mustard staining.

Example 15 In accordance with Example 13, a copolymer solution isprepared in xylene using the following: 46.90 parts of ethyl acrylate,37.35 parts of styrene, 9.40 parts of methacrylic acid and 6.35 parts ofpropylene oxide. The resulting copolymer solution (54.5 percent resinsolids) has a viscosity of Z Z and an acid value of 12.6 (solids basis).

This copolymer solution is mixed with a paratoluene sulfonamide-modifiedbutylated melamine-formaldehyde resin in a ratio of 70 parts copolymersolids to 30 parts resin solids. The sulfonamide-modified butylatedme1amine-formaldehyde resin solution at 66 percent solids in 34 percentxylene has a specific gravity of 1.06 and a viscosity of Z-Z The filmforming mixture of the copolymer solution with the melamine-formaldehyderesin solution is applied in the form of a film to steel panelspreviously coated with iron phosphate (Bonderite 1000). Films baked 30minutes at 250 F. have a pencil hardness of HB, pass the conical mandreltest but fail a 10-inchpound bump test. Films baked 30 minutes at 300 F.have a pencil hardness of F and pass both the conical mandrel andl-inch-pound bump tests.

Example 16 Following the procedure of Example 13, a copolymer solutionis prepared in Solvesso 100 1 using the following: 33.3 parts ofstyrene, 41.82 parts of ethyl acrylate, 14.88 parts of methacrylic acidand parts of propylene oxide. The resulting copolymer solution (55percent resin solids) has a viscosity of Z and an acid value of 13.2(solids basis).

This copolymer solution is mixed in a 70 copolymer solids, 30 resinsolids ratio with a butylated melamine formaldehyde resin solution,applied to Bonderite 1000 steel panels and baked for 30 minutes at 300F. The resulting slightly hazy film has a pencil hardness of 2H Solvesso100: A 95 percent aromatic petroleum hydrocarbon having a boiling rangeof 315 F. to 355 F. with 9 percent boiling between 315 F. and 338 F.

and good mustard, catsup, lipstick, solvent, and boiling waterresistance properties. When mixed in the same ratio with a butylatedbenzoguanamine-formaldehyde resin solution, the baked film has goodresistance properties and a pencil hardness of F. The butylatedbenzoguanarnineformaldehyde resin solution at 60 percent solids in 20percent butanol and 20 percent Xylene has a specific gravity of 1.04 anda viscosity of G-K.

Example 17 To a suitable reaction flask equipped with a mechanicalstirrer, thermometer, condenser and dropping funnel are added 50 partsof xylene and 50 parts of n-butanol. To the dropping funnel are added147 parts of styrene, parts of butyl acrylate, 45 parts of hydroxypropylmethacrylate, 18 parts of methacrylic acid and 6 parts of benzoylperoxide. Heat is applied to the flask raising the temperature of thesolvents to 90 C. Addition of the monomer-catalysts solution is begunand is continued for 3 hours and 5 minutes while the temperature of thereactants is allowed to rise to 120 C. Heating is continued at 120 C.for 2 hours and 12 minutes. 3 parts of benzoyl peroxide are added to thereactants and heating is continned at 115 C. to 120 C. for 3 hours and14 minutes. After the addition of 50 parts of xylene and 50 parts ofnbutanol, the resulting clear polymer solution has a viscosity of 2 at62.2 percent solids.

To 22.5 parts of the polymer solution are added 10 parts of a butylatedmelamine-formaldehyde resin (at 60 percent solids in n-butanol andxylene) and 7.5 parts of xylene. Films are prepared on glass using a 3mil draw down blade. After a 30 minute bake at 150 C., well cured clearfilms are obtained with good mar resistance, adhesion and gloss.

Example 18 To a suitable reaction flask equipped with a mechanicalstirrer, thermometer, condenser and dropping funnel are added 50 partsof xylene and 50 parts of n-butanol. To the dropping funnel are added156 parts of vinyl acetate, 90 parts of butyl acrylate, 9 parts ofmethacrylic acid, 45 parts of hydroxypropyl methacrylate, and 6 parts ofbenzoyl peroxide catalyst. Heat is applied raising the temperature inthe flask to 90 C. The addition of the monomer-catalyst solution isbegun and is continued over a 4-hour period while holding thetemperature at C. to C. Heating is continued for two hours with thetemperature slowly rising to 107 C. Additional catalyst, 3 parts benzoylperoxide, and solvents, 50 parts xylene and 50 parts n-butanol, areadded to the flask. Heating is continued at C. to 114 C. for 2.5 hours,The resulting clear product has a Gardner-Holdt viscosity of U to V at58.1 percent solids. Conversion of monomers to polymers is 97 percent ascalculated from the solids determination.

A blend is prepared from 24.1 parts of the copolymer solution, 10 partsof a butylated melamine-formaldehyde resin (at 60 percent solids inxylene and n-butanol) and 5.9 parts of xylene. Films are prepared onglass using a 3 mil draw down blade. After a 30 minute bake at C.,well-cured films are obtained having excellent flexibility, adhesion,mar resistance and gloss.

Example 19 Using the same procedure as described in Example 17, acopolymer is prepared from 96 parts styrene, 150 parts ethylacrylate, 45parts hydroxypropyl methacrylate and 9 parts methacrylic acid dissolvedin 100 parts of xylene and 100 parts of n-butanol using 9 parts ofbenzoyl peroxide catalyst. The copolymer solution has a viscosity of Zat 61.4 percent solids.

To 22.9 parts of the copolymer solution are added 12 parts of anisobutylated melamine-formaldehyde resin (at 50 percent solids inisobutanol) and 5.1 parts of xylene. Films on glass are prepared fromthis blend using a 3 mil draw down blade. After a 30 minute bake at 150C.,

clear, hard, well-cured films are obtained having excellent mareresistance and good adhesion, flexibility and gloss.

Example To a suitable reaction flask equipped with a mechanical stirrer,thermometer, condenser and dropping funnel are added 128 parts ofxylene. To the dropping funnel are added 150 parts of ethyl acrylate, 81parts of styrene, 60 parts of butyl, hydroxypropyl maleate, 9 parts ofmethacrylic acid and 12 parts of di-tertiary butyl peroxide. Heat isapplied raising the temperature of the xylene in the flask to 130 C. Theaddition of the monomer-catalyst solution is begun and is continued for5 hours and 7 minutes while holding the temperature at 124 C. to 130 C.The temperature of the reactants is then held at 124 C. to 136 C. for 6hours, after which heating period, 100 percent conversion of monomers tocopolymers is obtained as indicated by solids determination. Theresulting clear solution has a Gardner-Holdt viscosity of 2 22.9 partsof the copolymer solution, 8.0 parts of an isobutylatedmelamine-formaldehyde resin (at 50 percent solids in isobutanol) and 9.9parts of xylene are blended together. Films are prepared on glass platesusing a 3 mil draw down blade. After baking for minutes at 150 C., theclear films exhibit very good mar resistance, gloss, toughness, adhesionand flexibility. These films are unaffected after 8 weeks immersion in 5percent NaOH solution.

Example 21 Using the same procedure as described in Example 17, acopolymer is prepared from 186 parts of vinyl acetate, 60 parts ofdibutyl fumarate, parts of hydroxypropyl crotonate and 9 parts ofacrylic acid in parts of xylene and 50 parts of n-butanol using 9 partsof benzoyl peroxide catalyst. The copolymer solution has a viscosity of2;, at 70.9 percent solids.

To 19.8 parts of the copolymer solution are blended 10 parts of abutylated urea-formaldehyde resin (dissolved at percent solids in amixture of xylene and n-butanol) and 10.2 parts of xylene. Films areprepared on glass using a 3 mil draw down blade. After a 30-minute bakeat 150 C., films are clear and glossy.

Additional films are prepared in the same manner from a blend of 19.8parts of the copolymer solution, 10.2 parts of xylene and 10 parts of abutylated melamineformaldehyde resin (dissolved at 60 percent solids ina mixture of xylene and n-butanol). After a 30-minute bake at 150 C.,the films are clear and glossy.

Example 22 3 mols phenol-isocyanate equivalent weight=335) at 50% solidsin ethylene glycol monoethyl ether acetate parts copolymer to 20 partsdiisocyanate compound on solid basis). After addition of 24.1 partsethylene glycol monoethyl ether acetate, 3 mil films are prepared onglass. Well cured films with very good adhesion to the glass areobtained after 30 minutes at 180 C.

Another blend is prepared as described above wherein the ratio ofcopolymer to diisocyanate compound on a solids basis is 70 to 30. Films,prepared and baked as described above, are well cured and have very goodflexibility and gloss and adhesion to glass.

Example 23 A copolymer is prepared from 147 parts of vinyl acetate,

parts of butyl acrylate, 45 parts of hydroxypropyl To 26 parts of thecopolymer solution are added 2.4

parts of the diglycidyl ether of bisphenol A (epoxide equivalent weightl90), 11.6 parts of xylene and 0.2 part of a 60% aqueous solution ofbenzyl trimethyl ammonium chloride. Films are prepared on glass using a3 mil draw down blade. After a 30-minute bake at C., well cured clearglossy films are obtained having excellent flexibility and adhesion toglass.

To 26 parts of the copolymer solution are added 2.4 parts of thediglycidyl ether of b-isphenol A (epoxide equivalent weight=190), 0.2part of a 60% aqueous solution of benzyl trimethyl ammonium chloride and10 parts of an isobutylated melamine formaldehyde resin at 50% solids inisobutanol. After the addition of 11.6 parts of xylene, 3 mil films areprepared on glass and are baked at 150 C. for 30 minutes. Clear, wellcured films having very good mar resistance, excellent adhesion, andexcellent flexibility are obtained.

To 22.8 parts of the copolymer solution are added 9 parts of apolyisocyanate (adduct of 3 mols tolylene diisocyanate, 1 moltrimethylol propane and 3 mols phenol-isocyanate equivalent weight=335)at 50% solids in ethylene glycol monoethyl ether acetate. After theaddition of 8.2 parts of ethylene glycol monoethyl ether acetate, 3 milfilms are prepared on glass and are baked at C. for 30 minutes. Wellcured films having very good mar resistance and excellent flexibility,adhesion and toughness are obtained.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

[1. A copolymer of (a) 0.15 to 4.0 percent by weight of an unsaturatedaliphatic acid selected from at least one member of the group consistingof acrylic acid, methacrylic acid, crotonic acid and half acid-esters ofmaleic and fumaric acids formed with saturated alcohols of from 1 to 10carbon atoms, (b) 21 to 94.8 percent of at least one differentethylenically unsaturated monomer copolymerizable with the unsaturatedacid, and (c) 5 to 75 percent, the total being 100 percent, of a betahydroxy alkyl ester of an unsaturated aliphatic acid selected from atleast one member of the group consisting of acrylic acid, methacrylicacid, crotonic acid, and half acid-esters of maleic and fumaric acidsformed with saturated alcohols of from 1 to 10 carbon atoms, saidcopolymer having an acid value of from about 150.]

[2. The copolymer of claim 1 wherein (a) is acrylic acid, (b) is amixture of styrene and butyl acrylate, and (c) is hydroxy propylacrylate.]

[3. The copolymer of claim 1 wherein (a) is methacrylic acid, (b) is amixture of methyl methacrylate and ethyl acrylate and (c) is hydroxypropyl methacrylate] [4. The copolymer of claim 1 wherein (a) is butylhydrogen maleate, (b) is methyl acrylate, and (c) is hydroxy propylbutyl maleate].

[5. The copolymer of claim 1 wherein (a) is acrylic acid, (b) isstyrene, and (c) is 3-phenoxy, Z-hydroxy propyl acrylate.]

[6. The copolymer of claim 1 wherein (a) is acrylic acid, (b) is vinyltoluene, and (c) is 3-butoxy, 2-hydroxy propyl acrylate.]

[7. A composition comprising the copolymer of claim 1 in combinationwith a crosslinking agent] [8. The composition of claim 7 wherein thecrosslinking agent is a diisocyanate] 9. A copolymer of (a) 0.15 to 4.0percent by weight of an unsaturated aliphatic acid selected from atleast one member 0 the group consisting of acrylic acid, methacrylz'cacid, crotonic acid and half acid-esters of maleic and fumaric acidsformed with saturated alcohols of from I (0 I0 carbon atoms, (b) 25 to95 percent of at least one diflerem erlzylcnically unsaturated monomercopolymeriZ- able with the unsaturated acid, and (c)4.8 to 74.8 percent,the total being 100 percent, of a beta hydroxy alkyl ester of anunsaturated aliphatic acid selected from at least one member of thegroup consisting of acrylic acid, methacrylic acid, crotonic acid, andhalf acid-esters of maleic and fumaric acids formed with saturatedalcohols of from 1 to 10 carbon atoms, said copolymer having an acidvalue of from about 1-31.

10. A copolymer of (a) 0.15 to 4.0 percent by weight of an unsaturatedaliphatic acid selected from at least one member of the group consistingof acrylic acid, methacrylic acid, crotonic acid and half acid-esters ofmaleic and fumaric acids formed with saturated alcohols of from 1 to 10carbon atoms, (b) 25 to 94.8 percent of at least one diflerentethylenically unsaturated monomer copolymerizable with the unsaturatedacid, and (c) 5 to 74.8 percent, the total being 100 percent, of a betahydroxy alkyl ester of an unsaturated aliphatic acid selected from atleast one member of the group consisting of acrylic acid, methacrylicacid, crotonic acid, and half acid-esters of maleic and jumaric acidsformed with saturated alcohols of from I to carbon atoms, said copolymerhaving an acid value of from about 1-31.

References Cited patent.

UNITED STATES PATENTS 9/1938 Woodhouse. 7/1942 Neher et a1. 9/ 1943Neher et a1.

1 8 2,381,063 8/1945 Kung. 2,530,983 11/1950 Minter. 2,607,761 8/ 1952Seymour. 2,681,897 6/1954 Frazier et al 26086.l 2,729,615 1/1956 Bloomet :11. 2,777,832 1/1957 Mallison. 2,787,561 4/ 1957 Sander. 2,819,2371/19'58 Daniel. 2,842,519 7/1958 Ripley-Duggan. 2,853,462 9/1958Gaylord. 2,892,790 6/1959 Stuart et a1. 2,899,404 8/1959 Chapin et a1.2,939,854 6/1960 Christensen. 2,957,853 10/1960 Chapin et a1. 2,993,0327/1961 Stuart et al. 3,028,367 4/ 1962 O'Brien 260-775 3,082,184 3/1963Falgiatore et a1 260-851 3,002,959 10/1961 Hicks 26088.1 3,156,740 11/1964 Bossell 260855 FOREIGN PATENTS 1,061,952 4/1954 France. 1,038,7549/ 1958 Germany.

JOHN C. BLEUTGE, Primary Examiner U.S. Cl. X.R.

l17132A, 132BF, 161KP, 161L, 161LN, 161UT,

161UC, 161ZB; 26031.9R, 31.4EP, 32.8R, 32.8EP,

33.2R, 33.2EP, 33.4R, 33.4EP, 33.3UR, 33.6EP, 33.6UB,

33.6UA, 47UP, 77.5CR, 78.3UA, 78.5R, 7815B, 78.5T, 80.75, 80.8, 80.81,88.1PC, 831, 837R, 851, 856 859R UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION Patent No. RE 7 151 Dated June 29, 1971 Inventor(s) HICKS,DARRELL D1 It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:Add the following claims:

11. A composition comprising the copolymer of claim 9 in combinationwith a crosslinking agent.

12. A composition comprising the copolymer of claim 10 in combination Iwith a crosslinking agent.

13. The copolymer of claim 9 wherein (a) is acrylic acid, (b) is amixture of styrene and butyl acrylate, and (c) is hydroxy propylacrylate.

14. The copolymer of claim 9 wherein (a) is methacrylic acid, is amixture of methyl methacrylate and ethyl acrylate, and (c) is hydroxypropyl methacrylate.

15. The copolymer of claim 9 wherein (a) is butyl hydrogen maleate, (b)is methyl acrylate, and (c) is hydroxy propyl butyl maleate.

16. The copolymer of claim 9 wherein (a) is acrylic acid, (b) isstyrene, and (c) is 3-phenoxy, Z-hydroxy propyl acrylate,

17. The copolymer of claim 9 wherein (a) is acrylic acid, (b) is vinyltoluene, and (c) is 3-butoxy, Z-hydroxy propyl acrylate.

18. The composition of claim 11 wherein the crosslinking agent is adiisocyanate.

Signed and sealed this 21st. day of September 19W (sealO Attest:

I EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting officer. ActingCommissioner of Patents ORM 1, USCOMM-DC scan-pus 9 Y S. GUVCRNMENTPHNTNG DFFICE 1969 O-bub-J34

